Assembly of various goods, including various components and subassemblies of goods on an assembly line, requires the availability of the parts to-be assembled at the location of their assembly on the line. In many instances, transportable racks are used to transport parts to an assembly location. These racks can be moved to the location at which the parts are stored and loaded to various compartments, or areas, of the rack, often in manner corresponding to the order of their assembly. The racks are then moved to a specific location on the line where the included parts are needed. Because the parts are often removed from the rack by a human working on the line, the racks are limited in height to what is accessible by the average worker. Further, the number of racks on a line can be limited by the available area adjacent the various stations, as well as the number of racks that can be towed or otherwise transported in a “train” of such racks in one operation. However, such limitations may reduce the number of parts that can be provided to a line at a given time, which may increase the frequency with which racks must be swapped out for refilling. Accordingly, further advances are desired.